A visual search engine using facial recognition to help find images of people on the internet is expected to be introduced in 2007, the company behind the software said Tuesday.

The technology offered by Swedish startup company Polar Rose offers users a potentially more powerful tool for searching for images than Google's text-based image search, but some fear the new tool raises a host of privacy concerns.

The Polar Rose software can reconstruct a 3-D shape of a person's face and then combine it with the characteristics of the features to create a 'face print.'
(Polar Rose)

Polar Rose said its software can reconstruct a 3-D shape of a person's face and then combine it with the characteristics of the features to create a 'face print.' This image can then be used to search other photos for a match.

Visual search engines are new tools to the internet. Rather than searching for keywords in a photo caption to find an image, a visual search engine looks at the images themselves for common characteristics.

In November, California-based Riya released like.com, touted as the first visual search engine. It allows users to look at an image of a shoe, for example, and drag their cursor over the part of the shoe they like. The software will then show the shoes in their database with a similar look.

But Polar Rose's software raises different questions about privacy because the tool will be used to search for people.

Yaman Akdeniz, director of the U.K. non-profit group Cyber-Rights & Cyber-Liberties, told the New Scientist that the database would make it easy for government or other parties to track an individual.

"Although this sounds like a great idea, I would not like to be searchable in this way, or so easily tracked without my consent," said Akdeniz.

The software will be made available as both a browser plug-in and an application interface that can be integrated into other websites. The first website partnership is expected to be announced in January.